Locking device for folding chairs



Aug. 7, 1945. w. E. CLARIN 2,381574 LOCKING DEVICE FOR FOLDING CHAIRS 7Filed May 6, 1945 Patented Aug. 7,1945 I Werner Glarin; Ghicago; Ill-J,assijnor ofone 1 half tq AlierLJacobson, ChicagoglllaApplication-lMayyii,1943; Serial-.l io; 485,219,

"4Olai'ms. (01. 155-442)- V ,This inventiom relates to'ailocking'devicefor. .ptvotably ;connected1 -foldable andcollapsible membersparticularlyg as applied. to chairs; commpnlxfknowrnras the Y type;Chairspf thisk-ind; here i0iore:-i n; extensive;use; ihave been. withoutmeans for i efiectively lockingsthe seat-in horizontalposition and;the.;1egs;: in their 9X? tended) relationship; Consequently when suchvachainfisi subiectedlto :some-abnormalen extreme din'aryt usesity oftencollapses stand oxr-ithe seat A with the weightarearwandlyl 0t 3 the@XiSwOii thespiyotal connectioniofi the; seat ,to.

the legs, or when a person has tilted the; chair. baclg-iorritssrearlegs; Such strainsoitenmause a ehainot mannaneonates, .notiinfreqncntlytesu s l h n iniurie tia' e sf am to the cha r- The mainlohjectsj of ithis linvention therelore, a vIto. provide an; improved form andintercom? nection of. thetparts of a. f01dih chair wherebythe.seatfandleeswillibeg-locked automaticallyfand V positively in;their; extended positions I when the c i irgT nfol dedi to provide suchan 'improved interlockinggmechanism to 'tne chaiiiparts that the;interlockingrelationship, is easilyand? automatically. releasediwhen aneffort, isimade to fold v thechair; andto. providean iimplfovedfchair00115 Especially hasathis a hazardiwh n aiperson;hasattemptcd,=to

structionwith a mechanism of 'thiskindfwhich is i very simple andeconomicallto manufacture; and

which is. positive and facile, in operation.

Inthe particular embodiment herein shown:

fFig; l'is a perspectiveviewof the chair in its unflded'fpositiony iv Jv gj-2ffs1a fragmentary elevation taken from the inside' ofone of thelegs with the-p arts folded ,Or' collapsed? 2 Flgi sis a similar:view'with'thelegs inth'eir' 1 extended relationship; anctwith. theseat" ShOWll I dotted outline just before' the" locking emher-engagesits coacting shoulder;

legsmama 1 extended; the'seat likewise bein shown in dotted outline andthe locking member is n'iovedintdengageznent with its coacting shoulder?how the pin plates are Fig. 8 is a cross sectional view taken onithe:line 88- of =Fig,4 showing the pivotal connection oftherseattoth iront1egs;-'a;nd U

Fig.1 9-,-is a perspective View of the-metalcparts which; make: thepivotal. connection 3 showni in.

In the construction [wheres/1th. this improved locking; device. ,hasibeen related,i-the chairseom? prises; a pair. of '1 front:' leg' s l0 apair 0t l rear legs I hand ,awseat I2-. which-are pivotallx connedtedtogether; and. held inhtheir unfoldedfo seating position by.. a lockinginechanism lhereinaiter" de-, scribed v Therfrontlegs in a. ani ate neation;

v trated,' ..comprise apa'ir; or. strips; IBIland. M which are of. sucha len thiassto extendiagconsitlerable distance above the pivotal.connectionjioi these'at' I land are.- connected together.atltheinupnerend's by, the curved section I51; AQbaCKLreSt; L6; 1" e fcured in the, arcuate portionfbrmedby the sec tion l 5," This backrestalso s'erveslas afreiniorcin-g member to insure ,thenecessaryj rigiditym theunperends oithe legstrips l3'fand" M The lower ends of'the. legstrips [3 and) M re on. nested-by areinforcingbar, IT. This furtherinsures the rigidity} of these,stripsgand"provide'sif foot rest.Brackets .l8farerigidly securedtc the respective leg strips 1'3, and;Wat points above'the pivotalconnection ofi'the' seat 12; These brack;ets ext'ndirea ardly to providea pivotaisup' port forth'e rear legs H, ip

v Therea'r legs l'ljcon'iprisea pair cr mes-l s ens zg sim lar; toitliestrips; I33 n I 43* "but consider: ably; shorter: The? upper; ends orthese we strips I 9 and 211' are; pivoted? by suitable pins to" thebrackets" !8. Transverse 'reinforcing members 21 connect together thelower ends of thei'strips 19 The inner or" opposed iaces cfthe legstrips I 3- ami 20 each' have a slot 22 "extending lengthwise thereofslightly above the middle-portion *of tlie 1egs.- 'rneu-pper" ends ofthese 'slot's' terminate and 2"0"so' as to provide-thenecessarvjirigidity-to Whichconstitute one'of th'e partsofrtheinterwaringmecliariism hereinafter to be described The seat l2 as shown in thisembodiment comprises a panel 24 preferably of veneer constructionsupported between reinforcing strips 25, and 26. The strip 25 extendsacross the front and along the sides of the panel 24 whereas the strip'26 extends across the rear of the panel between the ends of the strip25. The seat is pivotally supported on the front legs ID by' means ofpivot pins 21' on which are mounted the angle-shaped reinforcing, spacermembers 28 and 29.

The plates 32 are secured to the rear corners of w the seat I2 by meansof pins or rivets 33 and 34 as will be noted from Figs. 5 and 6. Theplates are further anchored in place by means of strap members 35.secured to the back of the seat strip 26 by means of screws 36 and havetheir outer ends provided with hooks 31 which extend through recesses 38formed in the plates 32 adjacent the rear edges thereof. 1 M

The size, shape and pivotal mounting of the blocks or members 30resultsin thesemembers shifting into and out of engagement withythe shoulders23 as the legs of the chair are pulled into their final, fully extendedposition or are first shifted out of such fully extended position. Thisswinging or locking of the blocks or members 30 is caused by the rockingcontact of the upper ends of the members 30 with the upper ends of theslots 22 under the influence of the relative shifting of the front andrear legs near the extreme of their extended relationship. 7

The position of these blocks or members'30 just before they swing intoor out of the enlargement for engagement or disengagement with theshoulders 23 is shown in Fig. 3. The position of these blocks or members30 in theirengagement with the shoulders 23 for locking the seat andlegs in their unfolded and extended position is shown in Fig, 4.

It will be apparent from the foregoing description that a chair providedwith a locking means of this kind isvery secure against accidentalcollapse. This could not occur even 'by reason of allof the weight of aperson being placed on the seat rearwardly of the pivotal connectionWith'the front legs III, as would be the case of one standing on thechair seat. Neither could it occur by reason of one tilting back on therear legs I I.

Even though the chair parts are .thus securely locked in their. extendedpositions, the. locking mechanism is released by a very slightrearwardpressure on the forward edge of the chair seat or a pulling forward onthe curved back section witheven a slight pressure against the forwardedge of the seat I2. This will cause the blocks or members to shift outof contact with the shoulders 23 and permit their continued downwardmovement in the slots 22 as the seat and the consequent swinging of thelegs are shifted toward their folded positions, as indicated in Fig. 2.

Since certain changes may be made in the foregoing apparatus anddifferent embodiments of the invention may be made without departingThese straps have their inner ends,

Fix

from the scope thereof, it is intended that all matter describedhereinb'efore or shown in the accompanying drawingshall be interpretedas illustrative and not in a limiting sense.

I claim:

1. A foldable chair comprising pairs of legs hingedly connected togetherand siftable into and out of collapsed and extended relationship, onepair of said legs having slots extending longitudnally thereof andenlarged at one end to form offset shoulders, at seatpivoted on one ofsaid pair of legs shiftable relative to the other said pair of legs, andmeans slidable in said slots and pivotally connected to pins mounted onsaid seat so as to be shiftable transversely of said slots into and outof engagement with said shoulders when said means I engage theadjacent-ends of said slots, thereby releasably locking said seat andlegs in their extended positions.

2. A foldable chair comprising pairs of front and rear legs hingedlyconnected together and shiftable into and out of collapsed and extendedrelationships, each of said rear legs having formed in one facethereof alongitudinal slot the upper end of which is enlarged to provide an ofiset. shoulder, a seat pivotally attached between said front legs, andmembers pivotally mounted on said seat and slidably retained in saidrear leg slots, said members being shiftable into engagement with saidshoulders when said members engage the upper ends of said slots forreleasably locking said seat in its horizontal position and said pairsof legs are in their extended relationship.

3. A foldable chair comprising pairs of front and rear legs hingedlyconnected together and shiftable into and out of collapsed and extendedrelationships, said rear legs having formed in the opposed face thereoflongitudinal slots the upper ends of which are enlarged to provideoffset shoulders, a seat pivotally mounted inwardly of its rear edgebetween said front legs, outwardly disposed pins on the rear corners ofsaid seat, and blocks pivotally mounted on said pins and slidablyretained in the adjacent slots, said blocks being shiftable relative tosaid seat for engagement with said shoulders when said blocks engage theupper ends of said slots for locking said seat in its horizontalposition and said pairs of legs are in their extended relationship.

-a pin mounted on, said third member whereby one end of said block isshiftable into and out of engagement with said shoulder when theopposite end of said block engages the adjacent end of said slot forreleasably locking said members relative to each other.

WERNER E. CLARIN.

